them it's intended for the police or bar managers and should help them devise ways to reduce the risks by say assigning stewards at the right spots. people react best when spoken to directly even if they're drunk for example and in a critical situation when you need to get people out talking to them is far better than say posting a sign it custer's findings suggest that making space is safer might not always have to involve building work enough security personnel clearly visible and well positioned my twelve suffice to ensure that everyone remains safe where large crowds gather. safety also has a major role in medicine when you're proving new drugs for example to minimize risks and side effects new active ingredients are tested on animals as well as human. trials can take